That's an easy one- NOTHING! Unless you're in business or first, the pickings are pretty slim. My husband and I just flew back from my race in Orlando and if it weren't for the fact that we'd brought our own food, we'd not have had anything to eat for a good eight hours.
Small packs of hydrogenated pretzels and diet cola hardly constitute a healthy snack!
What's the answer? Again, bring your own food. If you're leaving from home, it's much easier than when you're returning from vacation, but even then, a little bit of thinking ahead and being prepared comes in really handy.
If you're outbound (leaving from home), prep food the day before so you can take it with you! Just as though you were planning your next day's meals to bring to work, steam your veggies, grill your fish, boil your eggs, wash your fruit and pack everything in small containers to take on the plane. I don't know what the current rules are about bringing food on board, but I will say that the only food item that I've had confiscated in the past year has been a bottle of Kombucha (since it was a liquid, and therefore, quite dangerous, of course!:). For the last flight, I brought a container of steamed kale, another of steamed broccoli, some apples and oranges, some hard boiled eggs, some sliced organic turkey and some raw walnuts, packed in a thermal bag with a few reusable ice packs. This proved to be plenty for both my husband and me and we suffered no bouts of blood sugar crashing or having to resort to eating junk.
If you're leaving from vacation and won't be able to cook or prep anything, not to worry! Stop by whatever local market you have access to and stock up on fruits, veg, raw nuts, bring them back to your hotel and simply wash them and you're set to go.
Finally, some airports, more than others, offer relatively healthy choices at some of their restaurants so if you're flying out of one such locale, you can take advantage of that and perhaps grab a salad with some clean protein, oil and vinegar on the side and some fruit.
Does this sound too complicated and time consuming? Well, it's not. Not if you've decided to make the choice to keep eating healthfully a priority all the time, and not to allow a lapse simply because you're going out of town!